Comments on: Polygamous Footprints in Our Genes http://spittoon.23andme.com/2008/09/26/polygamous-footprints-in-our-genes/ A receptacle for genetic knowledge. Sat, 13 Feb 2010 03:51:43 +0000 http://wordpress.org/?v=2.9 hourly 1 By: Pupsenok http://spittoon.23andme.com/2008/09/26/polygamous-footprints-in-our-genes/comment-page-1/#comment-1697 Pupsenok Sun, 05 Apr 2009 22:50:09 +0000 http://spittoon.23andme.com/?p=1452#comment-1697 I would expect that a further reason for the increased genetic diversity within the X chromosome to be due to the fact that women usually start reproducing at a younger age than men. Anecdotally, I have traced my own family line back some 500 years. Through a male-only line, this amounted to 15 generations, but through a female-only line, this amounted to 19 generations, or 27% more generations and this possibilities for mutation and diversity. This certainly would result in more mutations in a shorter period of time. In fact, all things being equal, this would make up almost entirely for the fact that there would only be 3 possible X chromosomes (and one Y chromosome) per generation making 33% less possible X chromosomes. It would have been interesting and more informative if a comparison of the diversity within the X chromosome and within the Y chromosome would have been done as well, rather than a comparison only against the 22 autosomal chromosomes, as the monograph indicates that the study seems to have done. I would expect that a further reason for the increased genetic diversity within the X chromosome to be due to the fact that women usually start reproducing at a younger age than men. Anecdotally, I have traced my own family line back some 500 years. Through a male-only line, this amounted to 15 generations, but through a female-only line, this amounted to 19 generations, or 27% more generations and this possibilities for mutation and diversity. This certainly would result in more mutations in a shorter period of time. In fact, all things being equal, this would make up almost entirely for the fact that there would only be 3 possible X chromosomes (and one Y chromosome) per generation making 33% less possible X chromosomes.

It would have been interesting and more informative if a comparison of the diversity within the X chromosome and within the Y chromosome would have been done as well, rather than a comparison only against the 22 autosomal chromosomes, as the monograph indicates that the study seems to have done.

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